Heated foot supports



July 24, 1956 Filed March 9, 1954 L. KONRAD ETAL HEATED FOOT SUPPORTS 2 Sheets-Sheet l y 1956 1.. KONRAD ET AL HEATED FOOT SUPPORTS 2 Sheets-Sheet 2 Filed March 9, 1954 L uise K ONPA D and K rl k/INZ United States Patent ce HEATED FOOT SUPPORTS Luise Konrad, Katzweiler, and Karl Winz, Kaiserslautern,

Germany, assignors to G. M. Pfatf A.-G., Kaiser'slautern, Germany, a corporation of Germany Application March 9, 1954, Serial No. 415,125 Claims priority, application Germany March 18, 1953 2 Claims. (Cl. 21919) The invention relates to foot supports, and relates more particularly to foot supports of the type that may be heated to keep warm the feet of a person.

The invention may be explained in connection with the foot treadle of a sewing machine, it being understood that this is being done herein only for the purpose of clarity and illustration, and that no limitation is thereby intended save as pointed out in the claims hereof.

It has been found that the working efiiciency of a sewing machine operator is considerably reduced when the operators feet are chilled. That may easily occur when a person operates a sewing machine that is driven by an electric motor, because the feet rest idly for a long time in the same position and this immobilization may bring about that the feet of the operator become cold. Even with treadle equipped foot operated sewing machines, however, operators have experienced a chilling of feet.

Attempts have been made in the past to ameliorate this condition by attaching to the treadle an exchangeable hot water container. Owing to the small dimensions of the treadle, however, the container needed to be small and required repeated time-consuming exchanges. This seems to be the reason why advocations for that proposed solution have long ceased.

It is among the objects of the invention to provide for a heated foot support that avoids the deficiencies of the prior art, is to easy to use, and dispenses with all exchanges.

Generally speaking, the invention provides for the building into the foot support of an electric resistance heat source, to keep the feet of the operator warm.

With the above and other objects of the invention in view, the invention consists in the novel construction, arrangement and combination of various devices, elements and parts, as set forth in the claims hereof, certain embodiments of the same being illustrated in the accompanying drawings and described in the specification.

In the accompanying drawings,

Fig. 1 is an underside perspective view, partly in section, of a pivoted sewing machine foot treadle in accordance with one embodiment of the invention;

Fig. 2 is a plan view, partly in section, of the embodiment shown in Fig. 1;

Fig. 3 is a plan view, partly in section, similar to Fig. 2, but showing a modification; and

Fig. 4 is a sectional view, taken on line 44 of Fig. 3.

In carrying the invention into effect in the embodiments which have been selected for illustration in the accompanying drawings and for description in this specification and referring now particularly to Figs. 1 and 2, there is provided a board 1 which may be fixed to the frame of a sewing machine. Bearing structures 2 are secured to the upper side of said board 1, and the body of a treadle 3 is tiltably pivoted to said bearing structures 2. The tilting axis of the treadle 3 is indicated at AB in Fig. 2.

At one front corner, the treadle 3 carries a bracket 4 2,756,318 Patented July 24, 1956 to which there is connected a rod 5 that supports and journals the lower end of a connecting rod 6. The connecting rod 6 is used for crank-turning the sewing machine in the well-known conventional manner (not shown in detail in the drawing).

A groove or recess 7 is provided in the body of the treadle 3. The recess 7 is arranged below the treadle cover 8, which provides the treadle top surface supporting the feet of the operator.

Electric resistance heating means are provided that comprise a cord 9, leads 14 and 16 and an electric resistor or resistance heater 18. The heater 18 is disposed in the recess 7 below the cover 8. The cord 9 is provided for connection to an electric source (not shown). The cord 9 may be attached to the board 1 by means of cable-clips 10, and protrudes into the body of the treadle 3 from the underside, through a lead-in bushing 12 that is mounted with its base 11 to the underside of the body of the treadle 3. On the interior of the body of the treadle 3, the cord 9 may be secured by means of a cable clamp 13. The two leads 14 and 16 branch out from a point near the cable clamp 13; the lead 14 is conducted to a contact point 15, while the lead 16 is conducted to a contact point 17. Between the contact points 15 and 17 there extends the resistance heater 18 in the groove 7.

The axis of the lead-in bushing 12 intersects the axis A-B of tilting of the treadle. This positioning of the bushing 12 has the advantage that the cord 9 will be subjected only to a minimum mechanical action during the treadle oscillations as it protrudes at the center of these oscillations, and will assure trouble-free operation of the heater throughout protracted periods of time.

A control switch (not shown) may be provided for connecting the cord 9 to an electric source and respectively for disconnecting it therefrom, and that control switch may either be for manual operation or for foot operation in accordance with well-known conventional principles.

In the modification shown in Figs. 3 and 4, there is provided a board 19 that supports two bearing structures 20 and 21. The body of a treadle 22 is tiltably pivoted in the bearing structures 20 and 21. In accordance with this modification, the body of the treadle 22 is of an open latticed construction, and the lattice openings extend throughout the thickness of the body of the treadle 22 in vertical direction. A bracket 23 is provided that holds a rod 24 to which there is connected a connecting rod 25. The connecting rod 25 corresponds to, and has the crank-turning function of, the previously described rod 6.

A heating means carrier 26 is provided that has a groove or recess 27, and a cover 28. The groove 27, as best shown in Fig. 3, is a labyrinth groove that is composed of sections; each section is connected with its ends to two adjoining sections, but is throughout its length spaced apart from said adjoining sections, and is spaced apart entirely from all the other sections of the groove 27. Brackets 29 are secured to the side edges of the carrier 26. Resilient means, such as springs 30, are connected to the brackets 29 and carry lugs 31 for removable connection of the carrier 26 to the body of the treadle 22. In the exemplification shown in Figs. 3 and 4, the lugs 31 have an over-turned edge and engage the terminal side edges of the body of the treadle 31. By these means, the carrier 26 may removably be positioned on treadle bodies of different size. The specific exemplitication of the lugs 31 with overturned edges shown in Figs. 3 and 4 may in accordance with an alternative modification be replaced by lugs that may engage recesses or slots in a treadle body (not shown in the drawing).

The carrier 26 is thus removably fastened to the underside of the body of the treadle 22, and heat emanating therefrom is conveyed through the openings of the lattice work to the feet of the bearer that rest on the top surface of the latticed body of the treadle 22.

1 A cord 32 is provided for connection to an electric source ,(not shown), and may be fastened to the board 19 by means of cable clips 33. There is again provided a lead-in bushing, designated 35, that is with its base 34 secured to the underside of the carrier 26 and the cord 32 is conducted through the lead-in bushing 35 into the interior of the carrier 26. Leads 36 and branch out from the cord 32 on the interior of the carrier 26, and the lead 36 terminates at a contact point 37, while the lead 38 terminates at a contact point 39. An electric resistor or resistance heater 40 extends between the contact points 37 and 39, and is disposed in the groove 27 of the carrier 26.

The operation of the above-described embodiments is as follows:

The operator will rest the feet on top of the body of either the treadle 3 or of the treadle 22. By operating a control switch (not shown), electric current will be fed from a source to the electric resistor or resistance heater 18 or 40, and the heat developed thereby will be conveyed to the feet of the operator to keep them warm.

The instant invention may be used not only in connection with new sewing machines, but may easily be applied to existing sewing machines.

a As mentioned earlier, not only may treadles of sewing machine of the foot-operated type be equipped with electric resistance heating in accordance with the invention, but the invention may also be applied to other foot supports where it is desired to keep warm the feet of the operator.

It will be apparent to those skilled in the art that the novel principles of the invention disclosed herein in connection with specific exemplifications thereof will suggest various other modifications and application of the same. It is accordingly desired that in construing the breadth of the appended claims they shall not be limited to the specific exemplifications of the invention described herein.

Having thus described the invention, what we claim as new and desire to be secured by Letters Patent, is as follows:

1. In a sewing machine treadle, having a tiltable body for the support of the feet of a person, in combination, said body having an apertured top surface, means disposed below said surface having a single labyrinth groove composed of sections, each section being connected with its ends to two adjoining sections and throughout its length being spaced apart from all sections, and an elongated electric resistor disposed in said groove.

2. In a sewing machine treadle, having a tiltable body for the support of the feet of a person, in combination, said body having an apertured top surface, a carrier removably connected below said surface to said body hav-' ing a single labyrinth groove composed of sections, each section being connected with its ends to two adjoining sections and throughout its length being spaced apart from all sections, and an elongated electric resistor disposed in said groove.

References Cited in the file of this patent UNITED STATES PATENTS 919,489 Stevens Apr. 27, 1909 1,287,356 Lawson Dec. 10, 1918 1,703,640 Schmidt-Predari Feb. 26, 1929 1,704,413 Wait Mar. 5, 1929 2,635,168 Lerza et a1. Apr. 14, 1953 any i- 

